As is well known, the smoke produced in a fire emergency can pose the greatest hazard to human life, since the occupants adjacent the area wherein the combustion is occurring will be unable to locate emergency exits or otherwise escape to safety, nor (in the event that escape is not feasible) will they even be able to locate and use any available fire suppression equipment such as portable fire extinguishers, blankets and the like. Particularly in a moving enclosed space such as the interior of a large passenger transport aircraft, the smoke will also result in an apparent loss of equilibrium, and will inevitably heighten the panic environment that would be expected under such conditions. Furthermore, the smoke is frequently accompanied by noxious fumes which may further impair visual acuity by irritating the delicate tissues of the human eye as well as impairing respiratory functions.
Cabin materials utilized in the construction of wide-bodied jet transport aircraft are normally tested for smoke emission values in accordance with U.S. National Bureau of Standards procedures utilizing a smoke chamber for providing a numerical measure of a particular material's propensity for impairment of visibility within the aircraft cabin as a result of the emission of smoke when the material is combusted. The combustion of certain types of such materials may also produce irritating gases which further impair human visual acuity. A report dated March 1974 entitled "Smoke Emission From Burning Cabin Materials And The Effect On Visibility In Wide-Bodied Jet Transports," Report No. FAA-RD-73-127 authored by Edward L. Lopez and prepared by the Lockheed-California Company Division of Lockheed Corporation under contract with the Department of Transportation, Federal Aviation Administration, Contract. No. DOT FA 72 NA-665, and published by the National Technical Information Service, Springfield, Va., lists smoke emission values for various types of aircraft cabin materials and details particular tests of human visual acuity during the combustion of materials having particularly high and low smoke emission values in a full-size mock-up of a section of a wide-bodied cabin.
As reported on page 13 of said Report, under the heading "Visibility Tests with Ventilation," the peak smoke densities and the smoke stratification effects during the combustion of smoke-emitting materials were somewhat reduced as a result of the normal air ventilation patterns within the cabin, with the air inlets located in the vicinity of the floor of the cabin and the outlets in the ceiling, but eventually the entire cabin would have severely restricted visibility.
To some extent, the deleterious effects of smoke occurring as a result of a fire aboard the aircraft may be suppressed by means of a mist of water such as is provided by my Stowable Fire Suppression System For Aircraft Cabins And The Like, disclosed and claimed in Co-pending application Ser. No. 335,228 filed on Dec. 28, 1981; however, for maximum effectiveness, the mist needs to be aimed at the source of the smoke. Also of interest is U.S. Pat. No. 4,391,017, "Device for Removing Incendiary Matter from the Interior of an Aircraft," by Applicant. Here, a flexible hose and nozzle are coupled to an outlet in the passenger compartment which is connected to the lower pressure external airstream allowing incendiary material to be "sucked" overboard.
Accordingly, there remains a need for an effective way to evacuate smoke from the interior of a passenger transport aircraft in flight promptly and efficiently so as to prevent any loss of visual acuity or equilibrium that otherwise would occur in the aircraft's occupants, thereby facilitating a proper response to the emergency and in any event reducing the panic conditions that could otherwise be expected to occur under such circumstances.